Experimental investigation of viscous effects on the deformation of oil droplets in turbulence

In recent years, much effort has been devoted to understanding the fundamental mechanism of bubble/droplet breakup in turbulent environment. However, relatively little attention has been put into the dynamics of deformation in turbulence, which contains clues to the interplay between bubble/droplet and eddies of various sizes. In this presentation, we will show experimental investigations of the deformation of oil droplets with various viscosity ratios ranging from 0.02 to 140 in turbulence, while surface tension is kept at a similar magnitude. We conducted 3D simultaneous measurements on both the droplet shape and the surrounding fluid flow, allowing us to study the complex couplings between slip velocity, local turbulence, droplet size, and 3D droplet deformation. These results provide new insights into how droplets/bubbles interact with turbulent eddies of various sizes.